U.S. patent number 5,342,519 [Application Number 08/099,906] was granted by the patent office on 1994-08-30 for fluid filter cartridge with replaceable filter element.
This patent grant is currently assigned to Donaldson Company, Inc.. Invention is credited to Francis A. Friedmann, Wayne M. Wagner.
United States Patent |
5,342,519 |
Friedmann , et al. |
August 30, 1994 |
Fluid filter cartridge with replaceable filter element
Abstract
A spin-on fluid filter cartridge with a replaceable filter
element is provided, comprising a housing, an internally threaded
annular collar, a replaceable filter element, and an externally
threaded mounting head assembly. The annular collar is secured
inside the housing at its open upper end. A sealing ring in an
annular channel adjacent the external threads of the mounting head
seals the cartridge when the mounting head assembly is threaded
into the annular collar.
Inventors: |
Friedmann; Francis A. (South
St. Paul, MN), Wagner; Wayne M. (Apple Valley, MN) |
Assignee: |
Donaldson Company, Inc.
(Minneapolis, MN)
|
Family
ID: |
22277187 |
Appl.
No.: |
08/099,906 |
Filed: |
July 30, 1993 |
Current U.S.
Class: |
210/232; 210/450;
210/452; 210/DIG.17; 210/453; 210/440 |
Current CPC
Class: |
B01D
35/30 (20130101); B01D 2201/302 (20130101); Y10S
210/17 (20130101); B01D 2201/304 (20130101) |
Current International
Class: |
B01D
35/30 (20060101); B01D 035/30 () |
Field of
Search: |
;210/232,440,443,444,452,453,450,DIG.17 ;55/502,510 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3933794 |
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Apr 1991 |
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DE |
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4022723 |
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Apr 1991 |
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DE |
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Primary Examiner: Savage; Matthew O.
Attorney, Agent or Firm: Merchant, Gould, Smith, Edell,
Welter & Schmidt
Claims
What is claimed is:
1. A reusable fluid filter cartridge, comprising:
(a) a housing having an annular peripheral wall, a closed end, and
an open end;
(b) an annular collar disposed in said open end of said housing,
said annular collar having internal threads and peripheral sealing
surface means adjacent said internal threads;
(c) means for securing said annular collar to said housing at said
open end;
(d) a replaceable filter element disposed in said housing to define
a fluid inlet chamber between said filter element and said housing,
said filter element having a hollow cylindrical core which opens to
a first end of said filter element, permitting filtered fluid to
flow therefrom, and having a closed second end, said filter element
having an outer diameter that is smaller than an inner diameter of
both said housing and said collar to permit removal of said filter
element through the open end of said housing; and
(e) a mounting head assembly having:
(i) external threads for mating with said internal threads of said
annular collar;
(ii) an annular channel adjacent said external threads;
(iii) a sealing ring disposed in said annular channel, said sealing
ring creating a first seal in cooperation with said peripheral
sealing surface means of said annular collar when said external
threads of said mounting head assembly are threaded into said
internal threads of said annular collar;
(iv) fluid inlet means extending through said mounting head
assembly in fluid communication with said fluid inlet chamber;
and
(v) a tubular filter attachment member extending into said open
first end of said filter element, said filter attachment member
having a fluid outlet port in fluid communication with said hollow
cylindrical core and an outer surface sealingly engaging said open
first end.
2. The fluid filter cartridge of claim 1, wherein said securing
means comprise a formed portion of said annular peripheral wall of
said housing formed over said annular collar, said formed portion
securing said collar in said open end of said housing.
3. The fluid filter cartridge of claim 2, wherein said sealing ring
disposed in said annular channel of said mounting head assembly is
biased against said formed portion of said annular peripheral wall
to create said first seal, said formed portion abutting said
peripheral sealing surface means.
4. The fluid filter cartridge of claim 2, further comprising means
for indicating positive sealing and for increasing clamping force
when said mounting head assembly is threaded into said annular
collar, said means for indicating positive sealing and for
increasing clamping force including a mechanical contact between
said mounting head assembly and said formed portion of said annular
peripheral wall of said housing.
5. The fluid filter cartridge of claim 1, wherein said housing is
deep drawn from sheet-metal steel and has a thickness of
approximately 0.030 to 0.050 inches.
6. The fluid filter cartridge of claim 1, wherein said fluid outlet
port includes internal threads, said mounting head assembly further
comprising means for providing a second seal when said filter
cartridge is installed by threading said fluid outlet port into
position, the clamping force of said first seal being sufficient to
overcome the clamping force of said second seal providing means so
as to cause said second seal providing means to release prior to
said first seal when said cartridge is removed.
7. The fluid filter cartridge of claim 1, further comprising means
for removing said mounting head assembly from said annular collar,
said removing means including an axially aligned aperture in said
mounting head assembly, said aperture being shaped to allow
insertion of a head removing tool to permit removal of said
mounting head assembly when said removing tool is turned.
8. The fluid filter cartridge of claim 1, wherein said annular
collar has a bevelled outer annular wall, the angle of said
bevelled wall relative a central axis of said housing being less
than the arctangent of the coefficient of friction between said
bevelled wall and said annular peripheral wall of said housing.
9. The fluid filter cartridge of claim 1, wherein said replaceable
filter element further has an annular end cap on said open first
end, said end cap having an inner edge defined by an opening in
said end cap to said hollow cylindrical core and a filter sealing
surface disposed adjacent said inner edge, said filter sealing
surface providing a radial seal with said outer surface of said
tubular filter attachment member.
10. The fluid filter cartridge of claim 9, wherein said filter
attachment member includes a shoulder which biases said closed
second end of said replaceable filter element against an interior
surface of said housing.
Description
FIELD OF THE INVENTION
This invention relates to fluid filter cartridges, and more
particularly, to a spin-on fluid filter cartridge with a
replaceable filter element.
BACKGROUND OF THE INVENTION
Filter cartridges for filtering fluids, such as engine oil, are
known in the art. Oil filter cartridges are used in internal
combustion engines to remove contaminants from the lubricating oil.
This reduces engine wear and promotes longer engine life.
The typical oil filter cartridge has a canister or housing with a
filter element contained therein which filters oil as it flows
through the housing. The housing typically has one end adapted for
attachment to the engine block by use of an internally threaded
centrally located fluid exit port that threads onto a corresponding
externally threaded configuration on the engine block. Oil flows
into the housing through fluid inlet holes surrounding the exit
port, and filtered oil is returned to the engine through the fluid
exit port. The cartridge is typically sealed to the engine block by
use of an O-ring gasket around the inlet holes. Fluid filters with
such an arrangement for attachment are referred to in the art as
"spin-on" filter cartridges.
Disposable or "throw-away" type fluid filters are known in the art.
The filter element is permanently sealed within the housing. When
the filter element has become clogged with contaminants, the entire
cartridge is discarded and a new unit is put in its place. This
type of filter is unnecessarily wasteful in that a whole new unit
must be used each time the filter cartridge is serviced. As only
the filter element has been expended, the useful life of the other
individual components has not been utilized. This results in a
substantial loss as to the cost of materials and labor that go into
manufacturing these components.
Much attention has been recently given to the adverse environmental
effects of throw-away filters. Many millions are disposed of each
year. Some are thrown in the trash and end up in landfills, often
with a substantial amount of oil still contained therein. State and
local governments have passed legislation to reduce the adverse
environmental impact of disposable filters. Some regulations
requires a 24-hour period of drainage to remove excess oil. Others
require crushing to reduce volume. In fact, regulations in many
areas treat used oil filters as "hazardous waste" requiring special
care in their disposal. Substantial fees are often charged for the
service of disposal of used filters, such fees often being as high
as one-half the purchase price of the filter.
An oil filter cartridge having a detachable cover to permit
replacement of the filter element itself is known in the art. U.S.
Pat. No. 5,066,391 discloses such a filter cartridge. However, such
prior art designs are relatively expensive in that a heavy gauge
outer wall for the housing and a separate bottom end cap are
required.
The present invention is concerned with a solution to these
problems. What has been needed is a simple, low-cost, easy to
manufacture, spin-on fluid filter cartridge with a replaceable
filter element.
SUMMARY OF THE INVENTION
According to the present invention, a spin-on fluid filter
cartridge with a replaceable filter element is provided. The filter
cartridge comprises a housing, an annular collar, a replaceable
filter element, and a mounting head assembly.
The housing has an annular peripheral wall, a closed end, and an
open end. The annular collar is disposed in the open end of the
housing and is secured to the housing. The annular collar has
internal threads and a peripheral sealing surface adjacent the
threads.
The replaceable filter element is disposed in the housing, defining
a fluid inlet chamber between the filter element and the housing.
The filter element has a hollow cylindrical core which opens to a
first end of the filter element, from which filtered fluid flows. A
second end of the filter element is closed.
The mounting head assembly has external threads, an annular
channel, a sealing ring, a plurality of fluid inlet ports, a
tubular filter attachment member, and a fluid outlet port. The
external threads of the mounting head assembly are for mating with
the internal threads of the annular collar. Adjacent the internal
threads is the annular channel in which the sealing ring is
disposed. The sealing ring cooperates with the peripheral sealing
surface to seal the fluid filter cartridge when the external
threads of the mounting head assembly are threaded into the
internal threads of the annular collar. The cartridge is mounted by
use of a centrally located internally threaded fluid outlet port in
the mounting head. A plurality of fluid inlet ports extend through
the mounting head. The tubular filter attachment member, in fluid
communication with the fluid outlet port, extends into the open
first end of the filter element.
Fluid enters the filter cartridge through the fluid inlet ports to
fill the fluid inlet chamber. It then moves radially inward under
pressure through the filter element and into the hollow cylindrical
core. The fluid, now filtered, moves upward in the hollow
cylindrical core, through the tubular filter attachment member, and
out of the cartridge through the fluid outlet port.
When it is time for the fluid filter cartridge to be serviced, only
the filter element is replaced and the remaining components can be
reused almost indefinitely. To service the filter cartridge, it is
first removed from its mount with the aid of any of various well
known tools, as with conventional spin-on cartridges. Oil can be
drained from the cartridge by inverting it as with conventional
spin-on throw-away cartridges. The mounting head is removed by
unscrewing it from the annular collar. The used filter element is
removed. The element can be recycled in many ways, such as
squeezing or crushing to extract more oil, shredding, and/or
incinerating. The housing and mounting head assembly are cleaned. A
new filter element is placed onto the tubular filter attachment
member and the mounting head assembly is threaded into the annular
collar and torqued appropriately. The fluid filter cartridge is now
ready for re-installation in the same manner as with conventional
spin-on throw away cartridges. The ability to reuse all of the
components of the filter cartridge other than the expended filter
element not only results in substantial cost savings, but also
reduces the adverse environmental impact associated with disposable
fluid filter cartridges.
The utilization of a separate threaded collar allows the housing to
be manufactured from a lower gauge material than if the threads
were cut into the housing itself. This in turn permits the housing
to be manufactured as a single unit, without the need for a bottom
end cap. Both of these aspects result in a substantial cost savings
above prior art devices.
These and other advantages and features of novelty which
characterize the invention are pointed out with particularity in
the claims annexed hereto. However, for a better understanding of
the invention and its advantages, reference should be had to the
drawings which form a further part hereof, and to the accompanying
descriptive matter in which there is illustrated and described a
preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is an exploded perspective view of a fluid filter cartridge
including a housing assembly, a filter, and a mounting head
assembly, according to the present invention.
FIG. 2 is an enlarged side view of the fluid filter cartridge shown
in FIG. 1 when assembled, a portion thereof being shown in section
and a portion thereof being broken away.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is illustrated one embodiment
of a spin-on fluid filter cartridge 10 with a replaceable filter
element 40. While the preferred embodiment is intended for use as
an oil filter for an internal combustion engine, the invention
could be used in a variety of applications for filtering fluids,
including hydraulics, fuel, and water. Cartridge 10 comprises a
housing 20, an annular collar 30, a replaceable filter element 40,
and a mounting head assembly 50.
Housing 20 has an annular peripheral wall 22, a closed end 24, and
an open end 26. In the preferred embodiment, housing 20 is
manufactured as a single unit. Housing 20 is deep drawn from sheet
metal steel, and preferably has a thickness of between 0.030 and
0.050 inches. While other materials and thicknesses could be
employed, these were chosen to minimize cost while providing the
necessary durability. The chosen gauge of housing 20 is
sufficiently rugged to withstand repeated use, yet sufficiently
thin to allow it to be formed to retain annular collar 30, as is
more fully discussed below. For comparison purposes, disposable oil
filters for automobiles and trucks range in gauge thickness from
0.010 to 0.020 inches.
Annular collar 30 is disposed in end 26 of housing 20. It includes
internal threads 32, peripheral sealing support surface 34 adjacent
internal threads 32, and bevelled outer annular wall 36.
Annular collar 30 is secured to annular peripheral wall 22 of
housing 20 at its open end 26. In the preferred embodiment, a
portion 23 of annular peripheral wall 22 is formed over, "spun" or
"crimped" onto peripheral sealing support surface 34 of annular
collar 30 to secure annular collar 30 within housing 20. Annular
collar 30 is supported by shoulder 25 of housing 20, which is
formed as a radially outward step in peripheral wall 22 of housing
20. However, those skilled in the art will recognize that annular
collar 30 can be secured to housing 20 in a variety of other ways,
such as crimping on a retaining lip or welding, thereby making
sealing support surface 34 a sealing surface.
Annular collar 30 includes bevelled outer annular wall 36. The
bevel angle is preferably sufficient to retain annular collar 30 in
housing 20 and to prevent collar 30 from rotating within housing
20. The angle of static friction between two surfaces is equal to
the arctangent of the coefficient of friction between the two
surfaces. Accordingly, the preferred bevel angle is less than or
equal to the arctangent of the coefficient friction between
bevelled surface 36 and annular peripheral wall 22 of housing 20,
measured from an axially upward direction along a central axis of
the housing 20. In the preferred embodiment, annular collar 30 is
machined from steel, and the resulting preferred bevel angle is 8.5
degrees.
Replaceable filter element 40 includes hollow cylindrical core 44
and annular end cap 43 at open first end 42. The filter media can
be of a variety of materials well known in the art. Annular end cap
43 opens to hollow cylindrical core 44 to define annular inner edge
46. Extending downwardly from inner edge 46 is filter sealing
surface 47. End cap 43, and particularly filter sealing surface 47,
is preferably of a resilient material capable of providing radial
sealing. In the preferred embodiment, end cap 43 is made of
urethane with a durometer of approximately between 70A and 80A.
Mounting head assembly 50 includes external threads 52, sealing
ring 55 disposed in annular channel 54, fluid inlet ports 56, fluid
outlet port 58, and filter attachment member 60. External threads
52 are for mating with internal threads 32 of annular collar 30.
When mounting head assembly 50 and annular collar 30 are threaded
together, sealing ring 55 is disposed against curled portion 23 of
housing 20 to seal filter cartridge 10. In the preferred
embodiment, peripheral sealing support surface 34 of annular collar
30 supports curled portion 23 and does not come in contact with
sealing ring 55. However, it should be recognized that sealing ring
55 could be sealed against peripheral sealing support surface 34 if
a different mechanism for securing annular collar 30 to housing 20
were employed.
In the preferred embodiment, a sealing stop 53 is provided on the
outer lower portion of mounting head 50. Sealing stop 53 provides a
positive mechanical indication of when filter cartridge 10 is
sealed. As mounting head assembly 50 is threaded into annular
collar 30, sealing ring 55 is seated and sealed when sealing stop
53 abuts curled portion 23 of housing 20. Sealing stop 53 also
increases the clamping force.
A plurality of fluid inlet ports 56 extend through mounting head
assembly 50 to receive fluid into filter cartridge 10. It should be
noted that fluid could also be received into filter cartridge 10
through a single fluid inlet port 56. In the preferred embodiment,
fluid inlet ports provide a second function in that they can be
used to assist in removal of mounting head assembly 50 from annular
collar 30. Inlet ports 56 are square holes, preferably 1/2" square
in size, to allow insertion of a mounting head assembly 50 removal
tool (not shown), such as an impact wrench or ratchet wrench.
Mounting head 50 is thus removed by gripping housing 20 and turning
the inserted removal tool. It should be recognized, however, that a
variety of inlet port shapes could be employed and that a separate
aperture could be provided for this purpose.
Fluid outlet port 58 includes internal threads 59 for mounting
filter cartridge 10. Filter cartridge 10 can be mounted as with
conventional spin-on oil filters by threading into place. Also, as
with conventional spin-on oil filters a second sealing ring 71 in a
second annular channel 70 surrounding fluid inlet ports 56 is
provided to seal filter cartridge 10 when threaded onto an engine.
Preferably, the clamping torque created by sealing stop 53 and
first sealing ring 55 should be greater than the clamping torque
created by second sealing ring 71. Otherwise, when housing 20 is
turned to remove filter cartridge 10, mounting head assembly 50
would remain in place causing oil to spill and requiring separate
removal of mounting head assembly 50.
When filter cartridge 10 is assembled, tubular filter attachment
member 60 extends into hollow cylindrical core 44 of filter element
40 at open first end 42. Filter element 40 and housing 10 define a
fluid inlet chamber 80 between filter element 40 and housing 10.
Fluid is filtered as it passes radially inward from fluid inlet
chamber 80, through the filter media, and through perforations in
the inner wall of filter element 40, to hollow cylindrical core 44.
Filtered fluid passes through filter attachment member and out of
filter cartridge 10 through fluid outlet port 58.
In the preferred embodiment, sealing between filter element 44 and
filter attachment member 60 is provided by a compressed fit between
outer surface 61 of filter attachment member 60 and filter sealing
surface 47 to create a radial seal. Alternatively, a sealing ring
could be employed between outer surface 61 of filter attachment
member 60 and filter element 40.
In the preferred embodiment, a shoulder 62 on filter attachment
member 60 presses closed second end 48 of filter element 40
downward and against bottom surface 28 of housing 20. This
arrangement eliminates the need for a spring which is typically
placed between the bottom surface 28 of housing 20 and filter
element 40 in order to bias filter element 40 upward to assure
proper sealing. Three positioning tabs 49, equally spaced at
120.degree. intervals on second end 48 are employed in the
preferred embodiment to support and center filter element 40.
It should be understood that the present invention is not limited
to the preferred embodiment discussed above, which is illustrative
only. Changes may be made in detail, especially in matters of
shape, size, arrangement of parts, and material of components
within the principals of the invention, to the full extent
indicated by the broad general meanings of the terms in which the
appended claims are expressed.
* * * * *